Effects of biochar combined with organic amendments on carbon composition and eco-enzymatic stoichiometry of red soil
[Objective]The objective is to analyze the effects of biochar and organic amendments application on organic carbon composition and enzyme activities of red soil in arid areas,and investigate limiting characteristics of microbial nutrients,so as to provide a theoretical basis for improving the stability of red soil organic carbon.[Method]A field experiment with 6 treatments were set up,including a non-amendment control(ck),corn(Zea mays)straw and sheep manure single application and their combination with biochar(corn straw biochar).2 years after the start of the experiment,soil organic carbon components,soil nutrient mass fraction,hydrolase activities and oxidase activities related to carbon,nitrogen and phosphorus cycling were determined.[Result]Compared with the single application of straw and sheep manure,the combination of biochar and its application significantly increased the mass fraction of soil organic carbon and available nitrogen(P＜0.05),increased the soil carbon-nitrogen ratio(C:N),carbon-phosphorus ratio(C:P)and the mass fraction of recalcitrant carbon pools,and reduced soil organic carbon activity index.The application of organic amendments significantly increased the activities of β-D-cellobiosidase hydrolase(CB),β-1,4-N-acetylglucosacosidase(NAG)and peroxidase(PERO)(P＜0.05).Compared with the single application of sheep manure,the combined application of biochar and sheep manure significantly reduced the β-glucosidase(BG)activity,leucine aminopeptidase(LAP)activity,NAG activity and acid phosphatase(PHOS)activity(by 50.9％,32.1％,45.3％and 40.0％,respectively,P＜0.05).Compared with the single application of straw,the combined application of biochar and straw reduced the activity of polyphenol oxidase(PHOX)by 28.6％and PERO activity by 22.2％,but had no effect on the activity of other enzymes.Compared with the single application of straw,the combination of biomass charcoal and straw reduced the vector length.Compared with applying sheep manure alone,the combination of biomass charcoal and sheep manure had no significant effect on enzyme stoichiometry,vector length,and vector angle(P＜0.05).PERO and PHOX were significantly negatively correlated with soil recalcitrant carbon pools,C∶N and C∶P(P＜0.05).Redundant analysis showed that soil recalcitrant carbon pools,C∶N and C∶P were the main factors affecting soil enzyme activity and its stoichiometric characteristics.[Conclusion]Compared with the single application of organic materials,the combined application of biochar and sheep manure can better improve the nutrient and the size of recalcitrant carbon fraction in red soil in arid cropland,reduce the activity of carbon degrading enzymes,and alleviate microbial carbon and phosphorus limitation,and can be an effective measure to improve the microbial nutrient limitations and carbon sequestration capacity in red soil.[Ch,2 fig.3 tab.44 ref.]
red soilorganic amendmentsbiocharcarbon componentsenzyme activity
万方数据
维普
